Separate listing for incorrect json and .desktop applets
After listing the "proper" applets, list those that have metadata.desktop, and then those that have a maetadata.json but is not correct (ie missing "KPackageStructure": "Plasma/Applet")
Unfortunately there isn't a way to get everything to list with a single query: either the desktop ones or the incorrect json ones will be missing.
Therefore put separate on one side the legacy queries, which will hopefully be possible to drop some day
Edited by Marco Martin